[ownedbycats]

I use a single library, split up into a couple of virtual ones. (Default, Physical Books, Documentation & Manuals, and Fanfiction. I also have VLs for Series and metadata cleaning.)

Advantages:
- I don't need to remember which library a specific book is in. I can just switch to All Books.
- No fuss about which library to put a book in if I have both the physical book and an eBook.
- A bit simpler to backup.

Disadvantages:
- If you're looking in the actual file structure, everything's kinda jumbled in together. For example, searching for a specific fanfic in Agent Ransack will also bring up my regular books.
- I have columns specific to specific formats (e.g. #fanficstatus, or #manualtype) that remain unused for other books. This likely bloats things a little more than necessary.
- While the custom categories that aren't applicable to the current VL are hidden, the VL-specific searches remain show.